Abacus



Oct. 20, 1953 s. F. DoN DERo ABACUS Filed March 28, 1952 2 Sheets-Sheet l INVENTOR A44a/Cefa 55'; Qa/w (paw,

ATTORN Y Oct. 20, 1953 s. F. DoN DERo 2,655,737

ABACUS Filed March 28, 1952 2 sheets-sheet 2 mn ruff m. 0, w NQ m M. O 2mm Mm w. K HY a 000 or\ ml.: m W l m w A, B v \\\w\,.\.f B AEF Patented Oct. 20, 1953 ABACUS Sylvester F. Don Dero, Baldwin, N. Y., assignor to Daintee Toys, Inc., Brooklyn, N. Y., a corporation of New York Application March 28, 1952, Serial N o. 279,145

4 Claims. l

This invention relates broadly to educational apparatus and more particularly to an improved construction of hundreds frame or abacus.

One of the objects of my invention is to provide an improved construction of hundreds frame or abacus including means for enabling either the instructor or the student to readily remove or add beads to the rods which slidably support the beads.

Another object of my invention is to provide Q an improved construction of hundreds frame or abacus in which a multiplicity of rod members, supporting slidable beads, are displaceably mounted in the frame enabling quick removal and replacement of slidable beads with respect to the rod members by an arrangement of spring means coacting with circular inserts or guides mounted in one side of the frame.

Still another object of my invention is to provide a construction of hundreds frame or abacus which may be readily packaged for shipment, in disassembled arrangement, including supporting means for readily assembling and erecting the device When unpackaged.

Still another object of my invention is to provide an educational appliance of the abacus type which may be readily manufactured inexpensively on a mass production scale and effectively utilized by both instructors and students, by adding to, taking from, or interchanging beads on different rods of the device for use in connection with new methods of mathematical teaching.

Other and further objects of my invention reside in the construction of hundreds frame or abacus as set forth more fully in the specification hereinafter following by reference to the accompanying drawings, in which:

Figure 1 is a front elevational view of my invention with parts of the frame broken away and illustrated in section for' more clearly showing the construction of the frame and the components constituting the mounting means and the displaceable arrangement of the rods which support the beads;

Fig. 2 is an end elevational view;

Fig. 3 is a vertical sectional view taken substantially on line 3-3 of Fig. 1;

Fig. 4 is a fragmentary vertical sectional view taken on line 4--4 of Fig. 1

Fig. 5 is a horizontal sectional view taken substantially on line 5-5 of Fig. l, and illustrating one of the displaceable rods in position for supporting the slidable beads, certain of the beads being shown in elevation;

Fig'. 6 is a view similar to the view illustrated 2 in Fig. 5 but showing one of the rods displaced in position for removing or adding slidable beads thereon;

Fig. 7 is a horizontal sectional view on an enlarged scale through the frame of the abacus and illustrating one of the displaceable rods foreshortened and mounted for endwise movement through a circular insert or guide operating against a compression coil spring Fig. 8 is a side elevational view of one of the circular inserts or guides and illustrating particularly the annular chamfered edge thereof for facilitating the mounting of the insert or guide in the frame of the abacus after installation of the compression coil spring in an aligned socket in the frame;

Fig. 9 is a vertical sectional view through the insert or guide shown in Fig. 8, the view being taken on line 9 9 of Fig. 10;

Fig. 10 is a front elevational view of the insert or guide shown in Figs. 8 and 9;

Fig. 11 is a side elevational view showing the construction of compression coil spring used in the arrangement of my invention;

Fig. 12 is an enlarged cross sectional assembly view of the supporting means and the abacus frame in assembled position;

Fig. 13 is a view of the abacus frame in disassembled position prepared for shipment and illustrating particularly the manner in which the supporting means may be mounted within the abacus frame for facilitating packaging and shipment; and

Fig. 14 is a vertical sectional View taken on line lll-I4 of Fig. 13.

In new methods of mathematical teaching being adopted by schools it is desirable when using a hundreds frame or abacus to provide means enabling either the instructor or the student to add to or take away from the individual rods of the abacus frame any number of slidable beads. It is also essential that such equipment be inexpensive in manufacture and production for meeting the available budget of educational institutions.

Wide distribution of the hundreds frame or abacus must be possible at low cost. I accomplish all of these requirements in the structure of my invention by providing erecting and mounting means which are readily removable from the hundreds frame or abacus and which may be installed within the frame and offer no projecting obstruction for facilitating packaging and shipment inexpensively. I provide mounting means for the multiplicity 'of spaced rods in the device consisting of circular guides or inserts which are readily mounted in one of the interior sides of the frame for retaining compression coil springs in position within spaced sockets in the frame for individually acting upon the ends o the rods for cushioning the rods while enabling axial or longitudinal displacement thereof for a distance sufficient to free the rods individuallyA from the frame While the ends thereof are guided by the circular inserts or guides to allow the slidable beads to be either removed from or added to the rods and the rods quickly replaced in latched position within the frame. The compression coil springs are shaped to provide end convolutions of reduced transverse section sucient to provide a resilient abutment for the end of the displaceable rod which projects through the circular guide or insert. I have found the construction illustrated herein highly practicable and effec? tive, but I desire it to be understood that no limitations upon my invention are intended and that the structure herein should be considered in the illustrative sense rather than in a limiting sense.

Referring to the drawings in more detail, reference character I designates the frame of the abacus formed by a pair of vertically extending end members Ia and Ib, interconnected by a pair of horizontally extending members Ic and Id. The horizontally extending member Id forming the bottom of the frame is provided with transversely extending recesses 2 and 3 therein, aligned with counter-sunk recesses through which screw threaded bolt members 4 and 5 extend.

The heads of the bolt members 4 and 5 are rebers Ia and Id. The width of the foot supports 6 and 'I is such that the foot supports clear the slidable beads Illa on the rods 9a and 9j, respectively, when the foot supports S and 'I are positioned in coplanar alignment with the rails Ic and Id. 'I'he foot supports 6 and I are initially 5 packaged with the frame I as shown in Fig. 13 by means of a suitable binding tape 6b and 'Ib by which the foot supports may be conveniently packaged in coplanar alignment with rails Ic and Id and shipped with the frame without offering projecting obstruction and also being ready for immediate assembly of the device.

In Figs. 1 3, 5, 6, l2 and 13, the foot supports G and I are shown in assembled position with the wing nuts 4a and 5a clamping the foot supports 6 and 'I within transverse recesses 2 and 3 and with the headed ends of the bolt members 4 and 5 countersunk within the horizontally extending member Id.

The vertically extending member Ia is provided with a multiplicity of horizontally extending spaced recesses shown at 8a, 8b, 8c, 8d, 8e, 8f, 3g, 8h, Si, and 89' for slidably receiving and retaining the ends of the spaced horizontally extending rods 9a., 9b, 9c, 9d, 9e, 9j, 9g, 9h., 9i and 9j. The horizontally extending rods 9ct-97 each slidably receive the groups of beads which I have represented at Illa, Ib, IOC, Id, IIJe, If, IUg, Ih, Iz' and Iy. The opposite ends of the rods 9ct-S fit within the circular inserts or guides il- 4 lustrated more particularly in Fig. 4 at IIa, IIb, IIc, Ild, Ile, IIf, IIg, IIh, IIi and IIy. These circular inserts or guides are shaped as shown more particularly in Figs. 8-10 to provide a chamfered annular peripheral edge as represented at IIa', facilitating the insertion of the circular insert or guide into the side wall of the end member Ib as shown for example by recess I2a in Fig. 7. The guide Ila'l is provided with a. surface coating or glue on the cylindrical surface thereof represented at I4. This glue adheres to the interior surface of recess I2a and retains the circular insert or guide shown at IlaI in position in end member Ib. The recesses represented at I2a are each aligned with horizontally extending sockets represented at I 5 in Figs. 5, 6 and l2. The sockets represented at I5 are in line with the recesses represented at 8a-8j in the vertically extending end member Ia. Before insertion of the guides I Ia-I I7' in position, a compression coil spring, represented at I6, is inserted in each of the sockets represented at I2a 'Ihe depths of sockets 8(187' in frame member I a are proportional to the depths of the aligned sockets I5 in frame member Ib, such that rod members 9a-j may be selectively displaced to the right against the pressure offered by the biasing springs I5 and through the inserts or guides I Ia-I Ij for a suiiicient distance to allow the ends of the rods Suf-9?' to clear the sockets Ila-8j and to be removed from the frame as represented in Fig. 6, or tilted at a sufficient angle to enable the slidable beads Illa to be removed from or in serted over the ends of the rods.. Thereafter the rods are selectively reinstalled by linearly moving vthe rods against the pressure of thecompression coil springs I6 through guides IIa-I I7' and the irst mentioned end. portion of Athe rods again reintroduced into sockets Erz-89' with the i coil springs I5 continuously biasing the rods to latched positions.

Each compression coil spring I8 is shaped to provide end portions of reduced section at II and I8 of a sufliciently reduced diameter as to abut with and bear upon the end of the aligned displaceable rods as shown for example in Fig. 7. That is to say, reduced section I1 of the coil spring I6 has a diameter that is slightly less than the internal diameter of the insert or guide Ila so as to eject the rod 9a through the insert or guide so that its remote end abuts with the end wall of the socket shown at 8a in end vframe member Ia. The guide IIa extends over the end of the socket I5 suiicently to confine the larger convolutions of the coil spring I6 and prevent the loss of the spring out of the frame member Ib. 'I'he compression coil spring I5 is symmetrically shaped at each end in order to simplify the assembly process.

Inthe operation of the abacus the rods are assembled as shown in Fig. 5 with the compression springs urging the rods linearly toward the left. When it is desired to remove or add tothe number o-f beads, the rod is moved linearly toward the right against the pressure of the spring and guided by the circular member or guide IIa freeing the end of the rod 9a from socket 8a and enabling the beads I0a to be removed froml or added to the rods. The several rods are manipulated in a similar manner enabling the number of beads to be increased or decreased on the different rods.- n

The hundreds frame or abacus-of my invention, together with the beads, are preferably manufactured from wood including the inserts or guides ila-l li, but the device including the inserts or guides may be made from molded plastic.

While I have described my invention in one of its preferred embodiments I realize that modiiications may be made and I desire that it be understood that no limitations upon my invention are intended other than those that may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is as follows:

l. An abacus comprising a frame provided with a socket in one end thereof, a rod having a multiplicity of co-acting slidable beads thereon, said rod having an end portion slidably insertable into said aforementioned socket, the other end of said frame having a recess therein, an annular guide apertured centrally thereof and inserted in said recess, a socket disposed behind said recess and in the last mentioned end of said frame, and a compression coil spring mounted in said socket and having the radius of the end turns thereof reduced in section and aligned with and bearing upon the end of said rod inserted through said guide for yieldingly biasing said rod linearly into engagement with the socket in said rst mentioned end of said frame.

2. An abacus as set forth in claim 1 in which said annular guide is provided with a chamfered peripheral edge facilitating the entry thereof into the recessed frame and in Iwhich said annular guide is maintained in the recess by a layer of cement for fastening the annular guide to the frame.

3. An abacus as set forth in claim 1 in which said compression coil spring has similarly disposed end turns formed on radii which are reduced for providing end turns of diameters substantially conforming with the diameter of the end of the rod which extends displaceably through the annular guide.

4. An abacus as set forth in claim l in which said annular guide has an external diameter exceeding the diameter of the aligned socket in the recessed frame and an internal diameter less than the internal diameter of the said aligned socket and substantially equal to the external diameter of the displaceable rod and wherein said compression coil spring has opposite end turns formed on radii which are reduced for providing end turns of diameters substantially conforming with the internal diameter of said annular guide and the external diameter of said displaceable rod.

SYLVESTER F. DON DERO.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 452,302 Denison May 12, 1891 532,282 Meyers Jan. 8, 1895 541,787 Hegewald et al. June 25, 1895 604,962 Breinl May 31, 1898 2,457,332 Wade et al. Dec. 28, 1948 FOREIGN PATENTS Number Country Date 12,314 Great Britain 1907 123,004 Switzerland Oct. 17, 1927 

